We will investigate the effects of cyclic nucleotides and related compounds on the outflow of aqueous humor in the rabbit and monkey. Experiments will include the measuring of intraocular pressure and outflow facility. We will attempt to identify the site of action of catecholamines by localizing the beta-adrenergic receptor as well as the mechanism of action of cyclic AMP. BIBLIOGRAPHIC REFERENCES: Neufeld, Arthur H., Dueker, David K., Vegge, Torgeir and Sears, Marvin L.: Adenosine 3',5'-monophosphate increases the outflow of aqueous humor from the rabbit eye. Invest. Ophthalmol. 14(1); 40-42, 1975. Neufeld, Arthur H., and Sears, Marvin L.; Adenosine 3',5'-monophosphate analogue increases the outflow facility of the primate eye. Invest. Ophthalmol. 14(9):688-689, 1975.